Lilies are generally tall except for several dwarf species, so that many species are unfit for potting, for instance, in a flower pot, with a conventional cultivation method. In lily cultivation, therefore, the production of lilies suitable for potting is achieved by using drawfing agents.
Paclobutrazol (trade name:Bonzi), Uniconazole (trade name:Sumagic), Ancymidol (trade name:A-Rest), Daminazid (trade name: B-NINE), Chlorocholine chloride (trade name: Cycocel) are used as dwarfing agents for many plants. Conventional dwarfing methods using dwarfing agents consist of spraying the agent on the stem and leaves or pouring the agent into the soil when the plant has grown substantially.
In addition to the dwarfing methods mentioned above, methods consisting of soaking bulbs or seeds in a dwarfing agent or using soil containing a dwarfing agent for cultivation (refer to:TOKKYO-KOKAI-KOHO (18-month Publication of Unexamined Patent Application) HEISEI 1 (1989)-153024 (hereinafter referred to as TOKKAIHEI 1-153024) and other methods are also known.
As for methods for dwarfing a lily, those consisting of conserving lily bulbs for a long period in a refrigerator (refer to: TOKKAIHEI 4-84836) or soaking bulbs in a dwarfing agent before planting are known.
However, problems have been reported for dwarfing methods which include spraying a dwarfing agent on the stem and leaves or pouring it into the soil because the dwarfing treatment can not be performed before planting the lily bulbs, and practioners need some experience and skill given that dwarfing is influenced by the date of treatment or the concentration of dwarfing agent etc.
On the other hand, the method of soaking lily bulbs in a dwarfing agent permits to the dwarfing treatment to be performed before planting, but it has been difficult to obtain uniform dwarfing results because lily sprouts may die, be dwarfed insufficiently or irregularly and similar problems have occurred depending on the dwarfing agent concentration or the treating time. Moreover, other problems such as the occurrence of lower leaves withering or the stem becoming weak have also prevented the method of lily dwarfing by bulb soaking to be practiced.
The present invention has been realized in view of the problems mentioned above and is intended to provide a method of lily bulb dwarfing treatment which can be performed before planting, practiced easily allows for a uniform dwarfing effect to be attained without any special experience and provides dwarfed, treated lily bulbs.